Case Study Report Nutrient recovery from digestate. June 2015



Similar documents
LIFE CYCLE ASSESSMENT ON COTTON AND VISCOSE FIBRES FOR TEXTILE PRODUCTION

FARMING FOR THE FUTURE How mineral fertilizers can feed the world and maintain its resources in an Integrated Farming System

February Biogas as a grid stabilising power source

Harvesting energy with fertilizers

Advanced Treatment of Hazardous Wastes(1) Advanced Treatment of Hazardous Wastes(2) Advanced Environmental Chemistry. Design of Solid Waste Landfill

Introduction to Waste Treatment Technologies. Contents. Household waste

Phosphorus Removal in Wastewater Treatment

Physical flow accounts: principles and general concepts

Birmingham City University / Students Union Aspects and Impacts Register. Waste. Impacts description

GUIDELINES FOR LEACHATE CONTROL

CHAPTER 9 PERMITTING. 9.2 Scotland Exemption Waste management licence PPC permit 102

Looking to the Future: 4 Danish scenarios for future farming

Use of Substitute Fuels in Large Combustion Plants (LCPs)

Papapostolou 1, E. Kondili 1, J.K. Kaldellis 2

an overview of trends and approaches

EMISSIONS OF AIR POLLUTANTS IN THE UK, 1970 TO 2014

TABLET DETERGENTS Towards A More Sustainable Future

ENERGY IN FERTILIZER AND PESTICIDE PRODUCTION AND USE

Farmer attitudes and potential barriers to the use of new organic fertilisers (Danish survey)

Digestate treatment in Sweden and Germany Applied technologies and technologies under research

State of affairs on Biomethane in the Netherlands National Roadmap

ANEROBIC DIGESTION and BIOGAS

Paragraph 9 Exemption The reclamation or improvement of land

Presented by Paul Krauth Utah DEQ. Salt Lake Countywide Watershed Symposium October 28-29, 2008

Municipal waste management in Austria

Eco- and water efficiency development prospects in Pulp-Board integrate.

Farming at dairy farms (produktion på mælkelandbrug)

9DORULVDWLRQRIHIIOXHQWVRIPDQXUHSURFHVVLQJ

Options for financing biogas plants

Living & Working Managing Natural Resources and Waste

Nutrient bookkeeping in Germany why?

This Questionnaire is divided into 8 sections referring to different capacity areas on the safe use of wastewater in agriculture:

Revealing the costs of air pollution from industrial facilities in Europe a summary for policymakers

LCA approaches for quantifying the environmental impact of plastics in the marine environment

Farm Animal Manure is an Important Sustainable Renewable Energy Resource

Ksawery Kuligowski Pomeranian Center for Environmental Research and Technology POMCERT University of Gdansk Poland

Examples for financing of biogas projects in Italy

A clean energy solution from cradle to grave

Natural and Advanced Treatment Systems for Wastewater Management at Municipal Solid Waste Disposal Site in Developing Countries

A NOVEL ION-EXCHANGE/ELECTROCHEMICAL TECHNOLOGY FOR THE TREATMENT OF AMMONIA IN WASTEWATER

Phosphorus inputs to Lough Neagh. The increasing impact of agriculture

Observatory monitoring framework indicator data sheet

The ECN Concept for Quality Assurance of Compost

How To Model Biomass

2.0 NEED FOR THE DEVELOPMENT & CONSIDERATION OF ALTERNATIVES

Green paper on the management of biowaste in the European Union

Wastewater Nutrient Removal

Air Pollution. Copenhagen, 3 rd September Valentin Foltescu Project manager air quality European Environment Agency


Phosphorus Removal. Wastewater Treatment

ReUseWaste WP6.3 Assessment of soil quality effects and nutrient availability of manure ash and biochar based biofertilisers

Evaluation of water stress of selected cases from water re-use or saving scenario s tested in SP5

Project website:

LCA EXPERIENCE IN THE FIELD OF RECYCLING OF PLASTICS FROM ELECTRONIC WASTE

UCD School of Agriculture Food Science & Veterinary Medicine Master of Engineering Science in Food Engineering Programme Outline

Energise your waste! EU legislation pushes for a reliable alternative to landfilling for residual waste. 13 th September 2011, Birmingham

Green Gases Practical concepts for reliable sustainable energy supply

Costs of air pollution from European industrial facilities an updated assessment

Poultry manure as a substrate for methane fermentation: problems and solutions

CONSORZIO ITALIANO COMPOSTATORI

Status of the World s Soil Resources

The Nitrogen Cycle. What is Nitrogen? Human Alteration of the Global Nitrogen Cycle. How does the nitrogen cycle work?

VISIT LOWER-SAXONY. Bruges, 12/05/14

Chapter 14 Quiz. Multiple Choice Identify the choice that best completes the statement or answers the question.

Government revenues due are foregone or not collected

How To Help The European People

Nutrient Removal at Wastewater Treatment Facilities. Nitrogen and Phosphorus. Gary M. Grey HydroQual, Inc X 7167

Energy from digester gas. Optimised biogas utilisation

Biomass Supply Chains in South Hampshire

The economics of micro-algae production

Using quality anaerobic digestate to benefit crops

x Amount of ammonia used for producing nitric acid (0.213 NH 3 /t AN + 6% efficiency loss)

Legrand's environmental commitments

USING HUMIC COMPOUNDS TO IMPROVE EFFICIENCY OF FERTILISER NITROGEN

Action Plan. Securing crop supply through whole crop purchasing

This fact sheet provides an overview of options for managing solid

Quality requirements and quality assurance of digestion residuals in Germany

Updated Guidance for Farmers on Requirements for the Storage and Spreading of Poultry Litter to 31 December 2014

WASTEWATER TREATMENT

Recovery of full cost and pricing of water in the Water Framework Directive

ASSESSMENT OF ALTERNATIVE WATER

Legrand's environmental commitments

AP ENVIRONMENTAL SCIENCE 2007 SCORING GUIDELINES

NAWARO BioEnergie AG: a short introduction into our business for BiG>East: Biogas for Eastern Europe

Nitrogen Fixing Bacteria in Agriculture Now a Real Option Guy Webb B.Sc. REM Agricultural Consultant

Biogas - Trends in Germany Biogas as a key in future energy systems

Proposed Terms of Reference for EIA studies

2050 LOW CARBON ECONOMY Executive Summary THE EUROPEAN CEMENT ASSOCIATION

Country specific notes on municipal waste data

Anaerobic Digestion: Biology and Benefits

These calculations are on a hectare basis or for a given size of an experimental plot.

AP ENVIRONMENTAL SCIENCE 2012 SCORING GUIDELINES

Introduction to our Business in Valmet. Marita Niemelä VP, Strategy Pulp & Energy 20 August 2014

Bioremediation. Introduction

Transcription:

Case Study Report Nutrient recovery from digestate June 2015

Improving sustainable biomass utilisation in North West Europe Colophon This report was compiled in the framework of action 3 of the ARBOR * project. Editors: Lien Loosvelt (POM WestVlaanderen, BE), Bram Vervisch (Inagro, BE) Authors: Lien Loosvelt & Brecht Vanhecke (POM WestVlaanderen, BE), Pieter Verdonckt, Bram Vervisch, Anke De Dobbelaere (Inagro, BE), Brecht Annicaert (Ghent University, BE), Cor van Oers (DLV Plant, NL), Katarzyna Golkowska & Daniel Koster (LIST, LU) This report further received input from the other ARBOR partners on specific aspects related to the regional transferability of the investigated case study results. Willem Dhooge (FlandersBio, BE) also helped with tet corrections and layout. * Arbor is an Interreg IVB NWE project with 13 partners from 6 European regions dealing with the development of technological solutions and regional strategy development for improved sustainable biomass utilisation. ARBOR is cofunded by local authorities from the United Kingdom, Flanders, Saarland, Luemburg, the Netherlands, and Ireland. Publication Date: 05 June 2015 Please check www.arbornwe.eu for the other reports that have been compiled within ARBOR: Five case study reports on a diversity of subjects like nutrient recovery, low impact energy crops, agro side streams, synergy parks and biomass closedloop systems. An update of the 2012 Benchmark report on biomass for energy use in NWE A strategies report on biomass for energy for regional authorities in the North West European region. 2 3

Table of Contents 1: Introduction to the case study 2: Inventory of nutrient recovery techniques 3: Physicochemical characterisation of recovered products 4: Field trials with recovered products 4.1 Open field trial with energy maize (2011) 4.2 Greenhouse trial with lettuce (2013) 4.3 Conclusions 5: Market for recovered products 5.1 Agricultural land 5.2 Domestic use: home garden products 5.3 Industrial endusers 6: National and EU policy assessment 6.1 European legislation 6.1.1 Fertilisers Regulation 6.1.2 Animal byproducts Regulation 6.1.3 Nitrates Directive 6.1.4 Regulation on organic production and labelling of organic products 6.2 Belgian & Flemish legislation 6.2.1 Royal Decree on Trade in Fertilizers, Soil Improvers and Growing Media 6.2.2 Flemish Manure Decree 6.2.3 VLAREM 6.2.4 VLAREMA 7: Economic assessment 7.1 Analysed systems and assumptions 7.2 Treatment costs, cash flows & fertilizing value 7.3 Conclusions 8: Environmental assessment 8.1 Aim of the study and analysed systems 8.2 Data and applied methods 8.3 The main outcomes 9: Transferability Questionnaire 8.1 Consumption estimate of manufactured fertilizers 9.2 Biogas and digestate production 9.3 What is the current use of the produced digestate? 9.4 What are the field eperiences with the use of digestate and derived products? 9.5 How does the status of digestate relate to animal manure at national/regional level? 9.6 Are there any subsidies for treating digestate? 5 6 6 7 7 8 9 10 10 10 10 12 12 12 12 13 13 14 14 15 15 15 16 16 12 20 21 21 21 22 24 24 24 25 25 26 26 1. Introduction Due to the historic presence of intensive livestock production and the limited amount of arable land for manure disposal, nitrate pollution in certain European areas is considerable. The European Nitrates Directive, implemented in 1991, intended to improve water quality in Europe by preventing pollution of ground and surface water by nitrate leaching from agriculture. This has forced local administrators and government to introduce stringent regulations regarding the use of manure (and later on digestate), resulting in national action plans and the defining of vulnerable zones. The Flemish action plan, for eample, consists of an obligation to process manure in such a way that the nitrogen present is not returned on Flemish agricultural soil after treatment, but is either eported, used on nonagricultural land (e.g. in gardens or parks) or converted to nitrogen gas or to a mineral fertiliser. These restrictions, combined with the presence of intensive livestock, imply that anaerobic digestion plants in Flanders (and other nutrient rich areas), may not, or only sparingly, return digestate as a fertilizer in its crude, unprocessed form and have to invest in digestate processing techniques. More recently, the focus in digestate processing techniques has switched from mere processing towards valorization techniques that recover a maimal amount of nutrients (N, P, K). This development is triggered by an increasing worldwide awareness of the depletion of mineral resources (such as phosphorus) and the volatile price of fossilbased mineral fertilizers. Mineral fertilizer use in Europe is high, even in regions with local nutrient surpluses where farmers pay to eport or destroy nitrogen in their farmyard slurry. The reason for this is twofold, first of all animal manure spreading is limited to 170 kg of N/ha according to the Nitrates Directive (in vulnerable zones) and second of all nutrient availability and composition in manure can differ from crop requirements. Estimates of the current phosphorus and potassium reserves are highly uncertain, but based on population growth and future nutrient demand, it is predicted that depletion will occur within 93 to 291 years for P and 235 to 510 years for K (Fien and Johnston, 2012; Van Vuuren et al., 2010; Villalba et al., 2008; Smit et al., 2009). Geopolitical moves can however shift this date forward, making nutrient scarcity an imminent threat which is eemplified by the fact that phosphorus was recently added to the EU critical raw materials list. A momentum has been created in which upcycling of digestate derivatives towards high quality fertilizers is aspired. The current challenges are to achieve optimal recovery and recycling of nutrients from digestate in a sustainable way enabling marketing and valorisation in an adjusted legal framework. 10: References 27 4 5

2. Inventory of nutrient recovery techniques In the framework of the ARBOR project, an inventory of techniques that have been tested either fullscale, pilot scale or lab scale, has been elaborated. For the full report Inventory: techniques for nutrient recovery from digestate by Lebuf et al. (2013), please see http://arbornwe.eu/downloads In the report the following definition for a nutrient recovery technique is proposed: techniques that create an endproduct in which nutrients are present in a higher concentration or different NPKratio than before processing or those that separate the envisaged nutrients from organic compounds, with the aim to produce an endproduct that is fit for use in chemical or fertiliser industry or as a mineral fertiliser replacement. From the nutrient recovery techniques discussed in the inventory report, only acid air washers, membrane filtration plants and ammonia stripping plants are currently working at full scale at anaerobic digestion plants in Flanders. However, they may need further technical finetuning, especially towards energy saving and chemical use. In addition, adjusting the process in a way that the characteristics of the endproducts can be made more clientspecific and more predictable, is an important challenge. A breakthrough in fullscale plants is to be epected for phosphorus precipitation. In the long run also electrochemical nutrient separation, several membrane separation techniques and biomass production could become part of commonly used digestate processing techniques. The etraction of phosphorus from ashes or biochar seems less promising, because it is questionable if combustion/ pyrolysis of digestate is a sustainable treatment option (due to nitrogen loss) and if this should be encouraged. However, etraction techniques could also be applied on the (dried) solid fraction of digestate. For all techniques described it is essential to put attention on their marketing value towards industrial or agricultural endusers. To be economically profitable, the treatment cost should be less than the current costs for manure disposal. Best case is that manure turns into a product with a positive value, for eample if the price allocated to the recovered nutrients is in accordance with the market price of N, P and K in mineral fertilizers. 3. Physicochemical characterisation of recovered products Despite the potential economic and ecologic benefits, closing nutrient cycles within the agricultural sector by introducing biobased fertilisers seems to be difficult to realise due to, among others, lack of insights in the composition and properties of these products. Consequently, within ARBOR a report was dedicated to the physicochemical properties of digestate and its derivatives and field eperiences. Below you can find a synthesis focussed on the following products which were used in the ARBOR field trials: ammonium sulphate, the liquid fraction (LF) of digestate, a miture of digestate and the LF of digestate, struvite and the effluent of constructed wetlands. Table 1: Physicochemical characterisation of the recovered products on a fresh weight (FW) basis, (n=2) DW (%) OC (%) ph EC (ms cm 1 ) TN (g kg 1 FW) Mineral N (%) TP (g kg 1 FW) K 2 O (g kg 1 FW) Pig slurry 10 42 7.8 35 8.1 69 2.4 4.4 Field trial Mi LFdig dig/lfdig 6.2 38 8.2 29 4.7 66 0.9 2.6 2.5 25 7.4 34 3.6 77 0.27 3.5 AmSul 4. Field trials with recovered products The recovered products as stated in point 3 were used in respectively an open field trial and a greenhouse trial. This kind of research is crucial to evaluate the impact of applying digestate derivatives instead of mineral fertilisers and/or animal manure (traditional fertilisation) on crop yield and soil quality and can serve as a katalysator towards farmers. 4.1 Open field trial with energy maize (2011) In this field trial eight different fertilisation scenarios were compared (Sc18) in four replicate subplots (n = 4) randomized on a 0.8 ha sandyloam field In Wingene. Based on the soil characteristics before the field trial, the fertilising advice was formulated at 150 kg ha 1 effective N, 270 kg ha 1 K 2 O and 30 kg ha 1 MgO. For phosphate, the maimum allowable dosage of 80 kg ha 1 for the cultivation of maize on nonsandy soils was set forward as described in the Flemish Manure Decree was respected (Vaneeckhaute et al., 2013). The setup summary of the field trial can be found in Table 2. 2.5 157 30 100 Effluent CW 0.46 3.2 7.8 7.1 0.02 15 0.004 1.44 AmSul= ammonium sulphate; dig= digestate; LF= liquid fraction; CW= constructed wetland Greenhouse trial Struvite LFdig 92 24 7.3 0.93 51.5 2.3 213 10.8 3.3 23 8.6 41 5.34 85 0.86 4.41 AmSul 33 50 2.4 262 85.8 100 0.11 0.18 Ammonium sulphate, which is waste water resulting from ammoniaremoval from manure or digestate using an acidic air scrubber, is a potential NSfertiliser. Reuse of the NKrich, but Ppoor liquid fraction of digestate after mechanical separation of raw digestate or a 50/50 miture of raw digestate and LFdigestate might be of important interest, since phosphorous application becomes more and more stringent in the European legislation (Vaneeckhaute et al., 2013). Furthermore, phosphorous can be removed from waste water and (digestate) slurry by adding magnesium, which results in the precipitation of ammonium magnesium phosphate (NH 4 MgPO 4 6H 2 O), also known as struvite, a slow releasing granular Pfertiliser. The current practice of struvite precipitation in Flanders, however, is limited to Premoval (precipitation) from industrial and municipal wastewater (Lebuf et al., 2013). Finally, the effluent from constructed wetlands (CW) is the endproduct of the final processing step, after biological treatment, of animal manure to dischargeable water that in large quantities can be used as a Kfertiliser (Sigurnjak et al., 2014). Scenario 1 (ref ) a 2 3 4 5 Mineral start b Table 2: Fertilisation scenarios (ton/ha) Mineral fertiliser c Animal manure AmSul Mi dig + LF dig LF dig In frame of ARBOR these products (and combinations of products) were used in open field trials and a greenhouse trial in Flanders. An elaborate description of the product characterisations and field eperiences can be found in the ARBORreport on physicochemical characterisation and market analysis of recovered nutrients from digestate. Below the key messages and observations are listed. Table 1 provides a summary of the key characteristics of the products under study. 6 7 8 AmSul= ammonium sulphate, dig= digestate, LF= liquid fraction a The reference scenario is traditional fertilisation with animal manure and synthetic (mineral) fertiliser b The mineral start fertiliser was ammoniumnitrate (27% N) c The mineral fertiliser consisted of ammoniumnitrate (27% N) and patentkali (30% K 2 O, 10% Mg). 6 7

In terms of crop yield no significant differences in the fresh weight of the crops were observed at the 5% level between the eight treatments. A similar observation was made with regards to dry weight and crop length. Overall scenario 7 showed the highest average dry weight yield and plant length throughout the whole eperiment. The different fertilisation scenarios had no significant impact on the biogas potential (m 3 ha1) of the energy maize at the harvest, although the energetic potential for scenario 47 was slightly higher as compared to scenario 13, due to the higher fresh weight biomass yield (Vaneeckhaute et al., 2013). Besides the impact on crop quantity and quality it is utmost importance to safeguard the impact of using digestate derivatives on soil fertility and soil quality. No significant differences in Nuptake by the plant could be observed, demonstrating that air scrubber water can be a valuable substitute for synthetic fertilizer nitrogen. Furthermore, nitrogen balances were similar for each scenario and in equilibrium, indicating that the amount of nitrateleaching was not influenced by the fertiliser type. However, modelling of Ndynamics with NDICEA showed that average nitrateleaching was slightly lower, ecept for scenario 7, compared to the reference (Vaneeckhaute et al., 2013). The P 2 O 5 content in digestate and derivatives seems to be more stable in time, which is interesting in terms of fertiliser application. Although significantly less P 2 O 5 was applied to the soil in scenario 46, a higher crop P 2 O 5 uptake was observed in these scenarios. This could be attributed to the higher relative amount of mineral P 2 O 5 to total P 2 O 5 in the digestate/lfdigestate miture (50/50) than in animal manure (Vaneeckhaute et al., 2013). Table 3 : Fertilisation scenarios (kg/10m 2 ) Scenario CAN 1a 2 3 4 5 1b 6 7 8 TSP Patentkali Struvite Amsul Individual treatment (Greenhouse 1) Combination treatment (Greenhouse 2) CW effluent LF dig A similar effect was found for K 2 O. The crop K 2 Ouptake was significantly higher for scenario 46 compared to the reference. Interestingly, in these scenarios approimately three times less synthetic K 2 O was used. This could lead to serious economic and ecologic benefits. As for P 2 O 5, also the relative amount of mineral K 2 O to total K 2 O was higher in the digestate/lfdigestate miture in comparison to animal manure (Vaneeckhaute et al., 2013). Net to N, P 2 O 5 and K 2 O, also S is an essential macronutrient for plants. However, too high doses of sulphate could also lead to salt accumulation in soils. In scenarios 2, 3, 5 and 6, where air scrubber waste water was used, the Ssupply was higher than the crop demand, resulting in a potential Ssurplus on the soil balance. Reversely, in the scenarios where no air scrubber water was used the crop demand was higher than the Ssupply by manure application, resulting in a net Setraction from the soil. Up to now no significant differences in soil Scontent and soil ph were observed during the growing season and at the harvest (Vaneeckhaute et al., 2013). For all reuse scenarios, the calculated economic benefits were significantly higher than for the reference (scenario 1), whereas the GHGemission and energy use were significantly lower. Therefore, the application of biobased fertilisers in agriculture can result in significant economic benefits for the agriculturist, as well as ecologic benefits regarding energy use and GHGemission reduction. The economic and ecologic benefits were the highest for scenario 8, respectively 3.5 and 4.4 times higher than the reference, since both synthetic N and K 2 O were completely eliminated in this treatment (Vaneeckhaute et al., 2013). More detailed information can be found in the ARBORreport on physicochemical characterisation and market analysis of recovered nutrients from digestate and Vaneeckhaute et al., 2013. 4.2 Greenhouse trial with lettuce (2013) In addition to fullfield scale testing the potential of using biofertilisers in a specific greenhouse setting was also eamined within the ARBOR project. This study was carried out in two eperimental greenhouses of the Provincial Research Centre for Vegetables East Flanders (PCG) situated in Kruishoutem, Belgium. The eperiment was a greenhouse assay, with a fully randomized design with four replication plots of 10 m 2 (4m 2.5 m) per treatment. Eight different fertilization treatments were established over two greenhouses (greenhouse 1: one on one replacement mineral fertilizer by biobased product, greenhouse 2: partial or complete replacement mineral fertilizer by combination of biobased products). Based on the soil characteristics before the field trial, the fertilising advice was formulated at 210 kg ha 1 N, 125 kg ha 1 P 2 O 5 and 240 kg ha 1 K 2 O. For each of the two greenhouses, conventional fertilization treatment using mineral fertilizers (treatments 1a and 1b) was included as a reference (Table 3). CAN: calcium ammonium nitrate; TSP: triple superphosphate; AmSul= ammonium sulphate; CW= constructed wetland; LF dig= liquid fraction digestate Physicochemical assessment of the lettuce showed no significant differences in crop uptake among the eight different fertilisation treatments. The crop nutrient content indicated that the applied biobased products can fulfil the total nutrient requirements of the crop. Evaluation of crop quality control parameters such as tipburn, yellow leaves, basal rot, bremia, leaf colour, uniformity and volume indicated no significant differences as compared to the reference at harvest time, which is crucial in marketability of the crop. However, in treatments 5 and 7 where LFdigestate was used as Nsource, the lettuce had a difficult start, which was still visible at harvest time. The negative influence was notable only with respect to lettuce uniformity and volume. This usually may be a result of two crucial variables in LF of digestate application: EC and the presence of ammonia. In terms of the soil quality and fertility no statistical difference (p > 0.05) was observed for the individual treatment substitutions (greenhouse 1). In contrast, significant differences were observed with respect to NO 3 N and available K in greenhouse 2, where partial or complete substitution was envisaged. In the case of complete substitution of mineral fertilisers in treatment 6, a significantly lower NO 3 N concentration was noticed with respect to reference 1b. This is a consequence of leaching by applying large volumes of effluent from CW ammonium sulphate as a K and N fertiliser on a moderate surface area of 10m 2. Calculations have indicated that the soil was watersaturated with the required application dosage, which may have caused nitrate leaching in treatment 6 during the growing period, resulting in a low nitrate content at harvest time. Furthermore, the significant difference in plant available K among the treatments in greenhouse 2 was a result of differences between treatments 6, 7 and 8 in which biobased products were applied. Individually, treatments 6, 7 and 8 were not statistically different as compared to a reference 1b. The results of this greenhouse trial indicate that biobased fertilizers can also be valuable in horticulture. Further research is however necessary to confirm these results. 4.3 Conclusions Recuperation and cradletocradle reuse of macronutrients from digestatederivatives is an important aspect in the further development of sustainable agriculture and anaerobic digestion. Our eperiences in the open field trial with energy maize as well as the greenhouse trial with lettuce indicate that the biobased products under study form valuable substitutes for mineral fertilizers, with similar performance towards crop production, soil quality and fertility. However, further research is necessary to assess the longterm effects and attention should be given to the form and nutrient concentration of the products as this can affect their applicability. These data form a good basis to open the debate of stimulating biobased products as nutrient supply in agriculture in European legislation. Further field research is ongoing in frame of different NWE projects (e Biorefine) and national projects (e MIP) to validate the results and to evaluate the longterm impact on soil quality. 8 9

5. Market for recovered products For a full market analysis, please read ARBORreport Physicochemical characterisation and market analysis of recovered nutrients from digestate. 5.1 Agricultural land In NorthWest European agriculture both nitrogen, phosphorus and potassium fertilizers are applied. Largescale recycling of nutrients derived from organic materials and using them as mineral fertilizers offers a lot of opportunities. However, some remarks should be made (Jaeken, 2012): Recovered substances often contain 35% N, whereas mineral fertilizers often contain up to 27% N. This can result in problems of storing large volumes of diluted recovered N products which means a higher operational cost. On top, questions rise about the stability of recovered N products during longer term storing. Products with a lower N concentration result in less accurate applications on the field. Another technical issue that should be dealt with is the lack of indepth knowledge on the plant availability of certain nutrients in recovered products, such as the ashes of combustion. One should have an eact idea of the solubility of the P present, as well as the plant availability and the amount of heavy metals present. Eamples of interesting products for fertilisation of agricultural land are: untreated digestate (NPKfertiliser), scrubber water ((NH 4 ) 2 SO 4 ), effluents from biological treatments (containing mainly K and Na), mineral concentrates (7 kg N/ ton, no P present) and struvite (mineral P fertiliser). 5.2 Domestic use: home garden products There are several types of home garden products, which could potentially be substituted by digestate and its derivatives. The composted solid fraction of separated digestate could be used in multipurpose garden composts for eample, or thermally dried and granular digestate could be used as a multipurpose organic fertiliser for gardens. 5.3 Industrial endusers Representatives of the mineral NPKindustry (producing nitrogen fertilizers, phosphoric acids, potassium fertilizers, ) agree that efficient use of raw materials is important. However, they put forward some requirements for the use of recycled products in their production processes. They need a homogeneous product in sufficient quantity with a constant composition. Furthermore there are several requirements regarding heavy metals and organic contaminants. In general, replacing fossilbased phosphorus by recovered phosphorus is deemed more feasible than the replacement of airborne nitrogen by recovered nitrogen. Producers of organic fertilizers and soil improvers also indicate some crucial aspects for recovery, such as the traceability of the products and phytosanitary requirements. In feed industry there s an interest in replacing soy by locally produced biomass. Research on algae, duckweed and the black soldier fly is being conducted, but when grown on digestate, there are several legislative hurdles to be tackled first. 10 11

6. National and EU policy assessment 6.1 European legislation 6.1.1 Fertilisers Regulation The Fertilisers Regulation ((EC) No 2003/2003) aims to ensure the free circulation on the internal market of EC fertilisers i.e. those fertilisers that meet the requirements of this legislation for their nutrient content, their safety, and their absence of adverse effect on the environment. The Regulation in its current form applies only to inorganic mineral fertilisers. It obliges a Member State to accept products lawfully marketed in another Member State unless the Member State of destination can demonstrate that the product poses a risk for human health or the environment (CSES, 2010). The Fertilisers Regulation does not affect other categories of fertilisers, i.e. national fertilisers, placed on the market of the Member States in accordance with national legislation. These include organic and organomineral fertilisers, liming material but also nonfertiliser products such as growing media and organic soil improvers. National fertilisers are covered by Regulation (EC) No 764/2008 on mutual recognition which ensures the intracommunity free movement of goods in the nonharmonised area. The Regulation is currently under revision as it does not encompass the whole fertiliser market. It has left an important and growing part of the market uncovered. The revised Regulation will widen the scope to include inorganic, organomineral and organic fertilisers, organic soil improvers, liming products, growing media, plant biostimulants and agronomic fertiliser additives. It will facilitate placing on the market both of organic products containing recycled nutrients (e.g. digestates, composts) and inorganic recovered phosphate products (e.g. struvite, incineration ash). However, clarification is still needed regarding the application of REACH for substances leaving the waste status, more specifically the eemption of certain REACH requirements for recovered products (art. 2(7)d of REACH). There is also a need for coherence with the Animal ByProducts Directive and the Nitrates Directive. The European Endofwaste criteria specify when certain waste products cease to be waste and obtain a status of a product (or a secondary raw material). It should be noted that if these criteria are not in place, wastes cannot cease to be waste (under the Waste Framework Directive 2008/98/EC) simply because they respect the Fertiliser Regulation requirements. Therefore they will still be regarded as waste. This means that wastes or products from processed waste would thus remain subject to traceability obligations and other relevant waste legislation unless they meet national endofwaste criteria (www.phosphorusplatform.eu). 6.1.2 Animal byproducts Regulation The Animal byproducts Regulation ((EC) No 1069/2009) lays down instructions for the collection, transportation, stockage, handling, use and removal of animal byproducts. Companies eecuting one of these activities have to be certified according to this Regulation. The Regulation also contains instructions for the trade and transit of animal byproducts and derived products. 6.1.3 Nitrates Directive In 1991 the European Nitrates Directive (Directive 91/676/EEC) was implemented for all member states. This Directive defines a limit of 50 mg/l of nitrate for surface water. If this limit is not respected in certain Member States they are being condemned by the EU and have to take certain measures. One of the causes of too high nitrates level in ground and surface water is the amount and the way of applying of animal manure. The Nitrates Directive defines a fertilizer as a substance containing a nitrogen compound or nitrogen compounds utilized on land to enhance growth of vegetation. It may include livestock manure, the residues from fish farms and sewage sludge. A chemical fertilizer is defined as any fertilizer which is manufactured by an industrial process. Livestock manure is defined as a waste product ecreted by livestock or a miture of litter and waste products ecreted by livestock, even in processed form. DG Environment (in charge of the Nitrates Directive) is preparing a report on the impact of digestate on water quality. The draft report shows that there are certain member states where digestate does not necessarily have an animal manure status, even if animal manure entered the biogas plant. This shows that the status of digestate is merely a national or regional interpretation of the Nitrates Directive (Grauwels, 2014). 6.1.4 Regulation on organic production and labelling of organic products To evaluate which types of digestate are allowed in organic farming practices, depending on the ingoing types of biomass, this regulation (Regulation (EC) No 834/2007) should be consulted. The following articles can be of importance: Article 4.b: Organic production shall be based on the restriction of the use of eternal inputs. Where eternal inputs are required, these shall be limited to: Inputs from organic production Natural or naturallyderived substances Low solubility mineral fertilizers Article 12.1.b: the fertility and biological soil activity of the soil shall be maintained and increased by multiannual crop rotation including legumes and other green manure crops, and by the application of livestock manure or organic material, both preferably composted, from organic production Article 12.1.d: in addition, fertilizers and soil conditioners, may only be used if they have been authorised for use in organic production under Article 16 Article 12.1.e: mineral nitrogen fertilizers shall not be used Article 16.1.b: The Commission shall, in accordance with the procedure referred to in Article 37(2), authorise for use in organic production and include in a restricted list the products and substances, which may be used in organic farming for the following purposes: as fertilisers and soil conditioners. Animal byproducts are divided into 3 categories according to their possible sanitary risks. Manure is labelled as category 2material. This means that the owners of a manure processing installation, who want to eport their products in the EU, have to be certified by a local certification institute. The endproducts have to be pasteurised before eportation (minimum 1h at 70 C) or the competent authority may authorise the use of parameters other than the parameters set out in point 1 of Section 1 of Chapter I of the Animal byproduct Regulation and other than the standard transformation parameters, provided that the applicant for such use demonstrates that such parameters ensure adequate reduction of biological risks. That demonstration shall include a validation. Animal byproducts have to be collected, transported and labelled according to the Regulation. During transportation a commercial document must accompany the animal byproducts. 12 13

6.2 Belgian & Flemish legislation 6.2.1 Royal Decree on Trade in Fertilizers, Soil Improvers and Growing Media The Fertilisers Regulation ((EC) No 2003/2003) aims to ensure the free circulation on the internal market of This federal law from 28/01/2013 regulates i.a. the trade within Belgium of endproducts of manure and digestate processing. It defines that a fertiliser should appear on the list in Anne I of the legislation to be traded. This list contains a description of the essential requirements for a fertiliser. If a certain product does not appear on the list, derogation can be requested. The Federal Government for Public Health, Safety of the Food Chain and the Environment is in charge of the derogation allowances. The Federal Agency for Food Safety certifies the companies trading fertilisers and checks if the fertiliser standards are complied with. 6.2.2 Flemish Manure Decree The Flemish Manure Decree is the implementation of the EU Nitrates Directive (1991). The Manure Bank is the administration responsible for the implementation of the Manure Decree. The Manure Decree has been adapted several times over the years as a result of different Manure Action Programs (MAP). In 2000 manure processing was introduced to reduce the manure surplus. In 2005 Flanders was condemned by Europe for not taking enough effort against nitrate pollution of surface waters. The condemnation led to a new Manure Decree which was introduced in 2007. In 2010 the third action programme (MAP3) ended and again the EC judged that the measures taken were not enough. On the 6th of May 2011 the new Manure Decree was adapted and approved by the Flemish parliament. In 2015 a new Manure Decree (MAP V) is epected to become valid. The Flemish Manure Decree defines manure processing as: Eportation outside the Flemish region of nonprocessed manure (only poultry/horse) or of other types of manure than poultry or horse, after specific approval by the receiving region or member state Eportation outside the Flemish region of processed manure Disposition of processed manure on nonfarming land (private gardens, parks, ) Conversion into a mineral fertilizer Conversion to N 2 Who has to process manure? Certain farmers belonging to a business unit with manure processing obligation. The manure processing obligation of a business unit in a certain year equals 0.6% for each 1000 kg net Nsurplus of that year. This number is augmented by a certain percentage depending on the regional manure production pressure (kg N/ha) Every farmer who produces more manure than there is available land in Flanders (this is more than the fraction with manure processing obligation) The objective of manure processing is to decrease the addition of nitrogen from animal manure and other fertilizers on Flemish arable land. Anaerobic digestion as such is not considered as a manure processing technique if the digestate returns to Flemish farm land since it still contains all the nutrients originally present in the manure. Only if the digestate is treated in a way that the conditions mentioned above are met, it can be considered as processed. 6.2.3 VLAREM All activities that can cause nuisance to local neighbours or the environment have to apply for an environmental permit. This is also valid for digestate and manure processing facilities. Vlarem divides all activities in categories, in order to make a distinction between less and more risk of hindrance. Each category represents an administrative procedure, with specific requirements and conditions. 6.2.4 VLAREMA In Flanders raw manure and processed manure is not considered to be a waste. However, installations that coprocess manure with organic waste are waste processors and for these endproducts VLAREMA applies. VLAREMA is the Flemish regulation for materials and wastes. For fertilizers and growing media that are derived from waste, it defines the maimal limits for inorganic and organic contaminants. 14 15

7 Economic assessment 7.1 Analysed systems and assumptions In the economic assessment, conducted by Luembourg Institute of Science and Technology based on data delivered by the Flemish partners, different eisting digestate treatment systems have been analysed. Composting (A) and drying and pelletizing plant (B) treat stackable substrate (solid fraction of the digestate) with dry matter content of 26 and 55% respectively. The other three systems deal with raw digestate with dry matter content of 911%. These are drying (C), biological treatment, reverse osmosis & drying at a single plant (D) or reverse osmosis and drying pilot plant (E). The analysed treatment systems allow recovering nutrients captured in the following intermediates (with a potential of becoming final products): compost, dried digestate, reverse osmosis (RO) concentrate and an ammonium sulphate (NH 4 ) 2 SO 4 solution. Currently for all technologies the intermediates are put together in a final product, which is a mi of ammonia sulphate or ROconcentrate with either compost or dried digestate. The rationale behind this miing pattern is linked to the current legal and market situation or client demands. The treatment costs analysis includes three groups of costs (ecl. VAT): total investment costs (buildings, installations, infrastructure, machines and land acquiring), operational costs (power and heat supply, materials, chemicals, internal transport, machine operating costs) manpower costs (plant workers) Each investment was calculated for 20 years and no subsidies or any form of financial support is considered in the analysis. The transport of substrate into the treatment plant was ecluded from the calculation. The sources of energy differ from plant to plant (biogas, natural gas, mied scenarios, etc.), which makes comparison of the concepts difficult. In order to make the analysis more transparent and transferable, the total electricity and heat demand was assumed to be satisfied by acquiring energy (power & heat) according to its market price for all the studied plants. More details regarding the study can be found in the paper Assessing the treatment costs and the fertilizing value of the output products in digestate treatment systems by Golkowska et al. (2013). 7.2 Treatment costs, cash flows & fertilizing value While comparing the total treatment costs (see Table 4) it becomes obvious that, in relation to the input volume, the treatment via composting (6 /tonne input) is much more economical than in the other systems, while the treatment costs for both drying plants B and C (14 /tonne input) are only slightly lower in comparison to biological treatment, reverse osmosis & drying plant D (16 /tonne input), even though there is a substantial difference in the input characteristics. It is also important to mention, that the costs of the pretreatment processes (realized before the substrate was delivered for drying and composting) and energy inputs are unknown and not included in this study (concerning plants A and B). For the reverse osmosis and drying unit E the input based costs reach nearly 38 /tonne input, however this plant runs in pilot scale, treating less volumes and using nonstandard technologies. Table 4: Treatment costs and fertilizing value of the outputs for different systems Parameter Unit A B C D E Input based treatment costs Output based treatment costs Potential fertilizing and humus value (PFHV) /tonne input /tonne output /tonne output 5.8 8.0 21.3 14.0 19.0 56.5 14.0 108.8 70.4 16.0 246.9 51.4 37.8 215.7 34.7 16 17

Since composting and drying plant B deal with stackable inputs with high dry solids content, the volume reduction during the treatment is much smaller than for the other plants treating liquid digestate. Consequently the specific treatment costs for these plants based on the input and output volumes do not differ so much as in comparison to other plants treating raw digestate (CE). For the latter ones the strong volume reduction during the treatment process results in strongly increased output based treatment costs. The treatment costs, which arise during the whole operating period, can be divided into costs contributing to the development of the region and those transferred out of the region. The largest part of the cash flow in each investment is linked to energy supply (2343%). Use of locally produced renewable energy e.g. from biogas instead of fossil fuel based energy can significantly enhance the regional cash flows. In general use of the locally sourced energy and involving local companies in the site construction together with the local manpower can contribute to the local binding of 7294% of the whole invested capital. This is important information to be considered by potential investors, which can have strong influence on creating local advantages of the treatment systems through local binding of capital and generating safe jobs in the field of green energy. The potential humus and fertilizing value (PFHV) of the treatment products was calculated based on their content of accountable N, P 2 O 5, K 2 O and HumusC as well as the current market prices for these nutrients. The calculated PFHV for the treatment products are compared in Table 4 with the annual specific treatment costs calculated on the product basis. This comparison shows that if the treatment products for plant A and B, dealing with stackable digestate, were to be sold at about 50% of their PFHV), the treatment costs would be completely covered by sale revenues. For plant C, D and E, even if the products would achieve their PFHV, there would still be costs of 0.612.6 /tonne input that would need to be covered either by the digestate suppliers or any form of financial subsidy. For all five scenarios the evaluation does not include any eternal transport costs (ca. 8.50 /tonne and 100 km), which either need to be additionally paid by the product end users or included in the treatment costs, which in case of plants treating raw digestate would either lead to increased substrate disposing prices or would have to be compensated by higher subsidies for the treatment installations. Considering current legislation and market situation for digestate treatment products in Europe, the PFHV may be considered a highly theoretical estimation. In practice, the price of digestate treatment products does not only depend on their quality, but also on the application sector (e.g. agriculture, horticulture, landscaping or hobby gardening), volume produced or geographical location (Barth, 2006; Kellner et al. 2011). In fact, many treatment plants are forced to give their products away for free, others manage to sell at prices ranging from 2 to 10 /tonne, while other plants eport over longer distances and sell their products for nearly 30 /tonne (including current transporting costs of ca. 8.50 /tonne and 100 km). 18 19

8. Environmental assessment 8.1 Aim of the study and analysed systems The environmental assessment of digestate composting (A), drying and pelletizing (B) and biological treatment, reverse osmosis & drying at a single plat (D), also discussed in chapter 7, together with ammonia stripping of raw digestate (F), considered as interesting future scenario for Flanders, was conducted at Luembourg Institute of Science at Technology 1. The main goal of this LCA study was to assess the environmental impacts related to the conversion of digestate from biogas production through different treatment technologies and the subsequent applications of the products on the fields, in comparison to the impacts attributed to direct spreading of digestate on fields. Since the four analysed treatment systems deal with different digestate fractions (raw digestate, solid fraction and pretreated solid fraction) the direct comparison between the systems was not possible. Consequently, the treatment systems were compared to the baseline scenarios, which for each technology included the same treatment steps of storage, transport and spreading but differed with regard to the digestate characteristics. The simplified chart flows of the analysed processing systems are presented in Figure 1. More details regarding the analysed systems and assumptions can be found in VázquezRowe et al. (2015) and Golkowska et al. (2015). 8.2 Data and applied methods 7.3 Conclusions Strategic planning of the treatment plant, considering use of the locally sourced energy, may lead to the regional binding of more than 70% of the whole invested capital, contributing to the development of the region by creating safe green jobs in the agricultural sector. Low demand for products derived from digestate treatment and their etremely low market price are not in accordance with their real fertilizing and humus value. Moreover, in the current market situation, the treatment costs for stackable predried digestate could be covered by selling treatment products even if less than 50% of the fertilizing value were to be returned. Treatment of raw digestate cannot be financed from the output revenues only, even if they would be sold at the market price reflecting the real fertilizing value of their components. Consequently, in the regions, in which, due to nutrient surplus in the agricultural soils, the authorities try to prevent an additional nutrient flow from digestate via digestate treatment (and eport), it can be necessary either to financially support the treatment plants or to introduce digestate disposal fees ( bringinfees ) to assure eistence basis for the treatment systems. The operational inputs and flow streams were relatively well characterized based on the data provided by the plant operators. For representativeness reasons the typical biogas digestate characteristics from Flanders was applied but considering the mass and nutrient balances according to plant operators or etracted from the literature (Bak, 2009) if the necessary data was not complete. The data linked to the background processes were obtained from the ecoinvent v2.2 (Frischknecht et al., 2007; Nemecek et al., 2007) database or other literature sources (Amon et al., 2006; De Mol et al., 2003; Deck and Deboosere, 2005; De Vries et al., 2012; IPCC, 2013; Rehl, 2012). The data were computed using the ReCiPe assessment method (Goedkoop et al., 2009)). Moreover, the impacts linked to toicity were analysed with the USEto assessment method (EC, 2010). The analysis included a broad range of impact categories, such as: climate change, ozone depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, human toicity, photochemical oidant formation, particulate matter formation, terrestrial ecotoicity, freshwater ecotoicity, marine ecotoicity, ionising radiation, agricultural land occupation, urban land occupation, natural land transformation, water depletion, metal depletion, fossil depletion. 1 The environmental analysis for drying (C) and reverse osmosis and drying pilot plant (E) was not possible due to incomplete data inventories 20 21

8.3. The main outcomes Treatment and spreading of the products generate much less environmental emissions than direct spreading of the untreated digestate for BS II and BS III linked treatment processes. Nevertheless, the most beneficial environmental improvements (higher reductions as compared to the baseline scenario) can be achieved in the plants treating raw digestate. In general for all the treatment systems 3 out of 18 analysed impact categories (i.e., climate change, particulate matter formation and fossil depletion) contribute to 95% of the final impact (s. Figure 2). From an environmental perspective, treatment of digestate through composting brings no significant environmental benefits about as compared to the spreading of untreated digestate. It mainly allows shifting the emissions from the field works in the BS I to the storage, treatment and the air treatment steps (s. Figure 2). Solid fraction of digestate (26% DM) STORAGE Baseline Scenario I (BS I) Tunnel Composting (A) Pretreated solid fraction (55% DM) STORAGE Baseline Scenario II (BS II) Drying and Pelletizing (B) The treatment of stackable pretreated digestate by drying & pelletizing allows reducing the total environmental impacts by 35% (s. Figure 2) as compared to the direct spreading (BS II). Although it causes more impacts in 13 categories and allows reducing impacts in 5 categories, the total positive result is mostly influenced by reductions in climate change and particular matter formation. The impacts avoided in these categories are mainly linked to an important reduction in ammonia emissions and are not counterbalanced by the considerable increase in the use of fossil fuels linked to the processing steps. Overall, treatment of raw digestate allows reducing total environmental impacts for scenarios D and F by 45% and 52% respectively as compared to the baseline scenario III (s. Figure 2). Where it comes to ammonia stripping, the increased use of fossil fuels and materials contributes to higher impacts in all toicity categories as well as for freshwater eutrophication, ionizing radiation and resources depletion. Nevertheless, a final reduction of the summary indicator, mainly due to significant reductions in particular matter formation and climate change (linked to substantial reductions of ammonia emissions), can be obtained. Also in biological treatment based processing the additional energy demand contributes to the increased impacts in majority of the analysed categories. Here the highest impacts are measured for fossil depletion, ozone depletion and ionising radiation. However, the substantial reduction in particulate matter formation and climate change overweighs all the other impacts and contributes to the significant improvement of the total environmental performance as compared to the direct spreading (SC III). More detailed analysis of the results can be found in VázquezRowe et al. (2015) and Golkowska et al. (2015). TRANSPORT COMPOSTING AIR WASHER compost (NH 4 ) 2 SO 2 solution TRANSPORT DRYER Dried Digestate AIR WASHER (NH 4 ) 2 SO 2 solution 14 12 Others FD SPREADING ON THE FIELD PELLETIZER 10 MD NLT SPREADING ON THE FIELD Pts 8 6 ULO ALO PMF Raw digestate (9 11% DM) Baseline Scenario III (BS III) Biological Treatment, Reverse Osmosis and Drying (D) Ammonia Stripping And Drying (F) 4 2 HT TA CC (EC) STORAGE 0 CC (HH) BS I A BS II B BS III D F TRANSPORT Solid phase SEPARATION Liquid phase Solid phase SEPARATION Liquid phase Figure 2: Results of the LCA assessment for the analysed treatment systems and baseline; FD Fossil depletion, MD Metal depletion, NLT Natural land transformation, ULO Urban land transformation, ALO Agricultural land transformation, PMF Particulate matter formation, HT Human toicity, TA Terrestrial acidification, CC(EC) Climate change ecosystem, CC(HH) Climate change human health (according to Golkowska et al., 2015) DRYER AIR WASHER BIOLOGICAL TREATMENT DRYER AIR STRIPPING Dried Digestate REVERSE OSMOSIS Dried Digestate AIR WASHER Concentrate EVAPORATION TRANSPORT (NH 4 ) 2 SO 2 solution SPREADING ON THE FIELDS TRANSPORT Mi Evaporate Figure 1: Treatment systems analysed through Life Cycle Assessment including the accompanying baseline scenarios 22 23

9. Transferability Questionnaire 9.1 Consumption estimate of manufactured fertilizers The total mineral fertilizer consumption in the EU27 amounted to 10.4, 1.0 and 2.2 million tonnes of nitrogen (N), phosphorous (P) and potassium (K) in 2011/2012 (Fertilizers Europe). Table 5 summarizes the consumption of mineral fertilizers in the Benelu, Germany, Ireland and the UK. When focussing on the countries under study, statistics of the period 20002008 indicate that the consumption of N and P mineral fertilizers has decreased for all countries under study and most in the Netherlands (N: 4.3%) and Luemburg (P: about 10%). However when one takes in account the kg of nutrients per hectare of utilised agricultural area the Netherlands report the highest use of mineral fertiliser, closely followed by Belgium, Luembourg and Germany and Ireland which all have an average mineral fertiliser use of over 100 kg/ha. Belgium 1 Germany Ireland Luembourg 2 Netherlands UK 9. Biogas and digestate production In general 3 major biogas installations types can be distinguished, namely agricultural, sewage sludge and landfill based plants. In Germany and Luembourg agricultural based plants form the majority in type and energy production, while Belgium and the Netherlands have mied shares of the different biogas plant types and consequent energy production. Remarkably, the UK and Ireland have a rather high share of biogas plants running on sewage sludge, while the vast majority of biogas production is derived s (s. Figure 3). The respective numbers of digestate production are represented in table 6. However one should be careful to directly link these numbers to valorisation potential. For the moment digestate is a container concept, with no guarantees towards quality assurance. The quality and composition varies from digester to digester and is strongly dependent on the feedstock. Flanders is one of the strongest in quality assurance, but in other countries this is only poorly elaborated or quasi noneistent. Phosphorus 5 500 108 000 22 000 500 10 000 82 000 Source: Eurostat, 2012, ecept 1 Eurostat, 2010, 2 Eurostat, 2011 Table 5: Overview of mineral fertilizer consumption (ton) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Potassium 320 000 75 000 32 000 215 000 Nitrogen 143 500 1 640 000 356 000 15 000 233 000 1 000 000 BEL GER IRE LUX NED UK other landfill sewage agriculture Figure 3: Biogas plants in European countries in 2013 subdivided by type (redrafted from Source: EBA 2014) Table 6: Annual digestate production (based on total input capacity 0.9) Belgium Germany Ireland Luembourg Netherlands UK Flanders Walloon Region Tonnes of digestate 2 010 600 1 86 250 000 unknown 215 000 2 1 400 000 3 1 BiogasE, Voortgangsrapport 2013 2 ASTA (Administration des services techniques de l agriculture), 2012 3 WRAP (2013). A Study of the UK Organics Recycling Industry in 2012. Waste and Resources Action Programme, Banbury, UK. 9.3 What is the current use of the produced digestate? Digestate is most frequently spread out on agricultural land, as an organic fertiliser for crops, used in the same way as animal slurry, with similar spreading techniques. Similar to slurry, it is sometimes necessary to store the digestate for application at appropriate times (due to the spreading window, spreading is generally not allowed in winter times). In Ireland, Luembourg, the UK, and also Germany, almost all digestate is spread out on agricultural land. All member states have quality standard protocols for digestate, among other things to ensure it being free from pathogens, chemical and physical contaminants. However, in some member states, digestate is also further treated. There are 2 main reasons for this. It can either be done to increase the usefulness of the fertiliser itself by separating it into a fibre and solid fraction (as in Ireland), or it can be done in Nitrate Vulnerable Zones (NVZ) with limited field spreading of nitrogen coming from organic manure. In these NVZ, often animal manure field spreading competes with digestate, as they both contain significant amounts of nitrogen from organic origin. As a consequence the nitrogen present in the digestate has to be either converted into an inorganic form, or transported to regions that have a lower abundance of fertilising nutrients locally available. Conversion can be done through denitrification to N 2, or through ammonia stripping and subsequent scrubbing. For long distance transport, digestate is often composted, dried and/or palletised. Mainly in Flanders, but also in the Netherlands and in some regions in Germany (Lower Saony, partly Schleswig Holstein and border area of North Rhine Westphalia), digestate is being processed. Techniques used in Flanders are separation, drying, microbiological nitrification/denitrification, ammonia stripping and scrubbing, membrane filtration, composting, Large amounts of digestate are being eported. The same is valid in the Netherlands, but to a lesser etent. In Germany digestate transfer is mainly eecuted within the country, as a cooperation amongst federal states. Separation and drying are the most commonly applied techniques in Germany. 9.4 What are the field eperiences with the use of digestate and derived products? Throughout the NWE region digestate is considered as a valuable and attractive fertilisation product. This can be eplained by the higher ratio of mineral N to organic N as compared to raw manure which makes the nitrogen more crop available early in the season. Furthermore the organic fractions available in digestate can contribute to the soil organic matter enhancing the soil structure. More and more farmers have access to digestate and its byproducts and there is an increased interest in the benefits and challenge of using these products on the field. In general farmers are satisfied when using these products as they can be easily spread by the eisting machinery and the odour emissions are minor to manure application. Drawbacks however are the uncertainty regarding nutrient content as this is highly dependent on the feedstock of the digester and the legal status of digestate (see 9.5). 24 25

As digestate is a relative new fertilisation product there are still uncertainties regarding their long term effect on the soil. A specific attention point here is the fear for soil compaction when used in (relatively) wet climates on predominantly medium/heavy soil types (that are poorly drained) (e. UK and the Netherlands). In several countries there are field trials ongoing in which digestate and its byproducts are compared to classic fertilisation schemes. Flanders and the Netherlands have an etensive number of field trials regarding this topic. For Flanders the results of these tests are elaborated in this report and other field trials can be consulted via the following links: http://www.vcmmestverwerking.be/informationfiles/bijlage_02_karakterisatiedigestaten_povlt.pdf (in Dutch) http://www.biorefine.eu/biorefine/downloads The results for Germany and the UK can be found on respectively www.tll.de EVAProject/University of Hohenheim and http://www.wrap.org.uk/dcagri. In Luemburg there are also field trials running under the Interreg IVa project ECOBIOGAZ to investigate the fertilizing potential of N captured in raw digestate, solid and liquid fraction of digestate as well as dried digestate in comparison to commercially available mineral N fertilizers. Additionally, long term influences on the soil quality will be investigated. More detailed information can be found via the following links: http://www.ecobiogaz.eu/nos4actions/nouvellesrecherchesenaval/ (in French) http://www.ecobiogaz.eu/nos4actions/promotionsousproduits/ 9.5 How does the status of digestate relate to animal manure at national/regional level? In Flanders, Ireland and the UK digestate coming from a digester that takes in manure is considered 100% animal manure. In Nitrate Vulnerable Zones, this means a limit of 170 kg N/ha. However, if no livestock slurry is included, the resulting digestate has another status (called differently in the different member states), which allows appliance over the 170 kg N/ha limit, but is still subject to field spreading rate limits (e.g. 250 kg N/ha). The Netherlands account for total N in digestate as animal manure if at least 50% of the input material is livestock manure and the comaterial is part of a specific list. According to the German Düngeverordnung the limit of 170 kg N/ha is not eligible for digestate, if the input material is not defined as Wirtschaftsdünger. Currently energy crops are not Wirtschaftsdünger. According to the planned amendment of the German Düngeverordnung in 2014, it is epected that also digestates deriving solely from energy crops will become subject to the N limitations of 170 kg N/ha. If digestate comes from a miture of manure and energy crops only the amount of nutrients coming from manure are taken into account for the 170 kg N/ha limit. This will be changed by the amendment of the Düngeverordnung 2014, and the total nutrient amount in the digestate will be accounted for. In Luembourg all digestate, independent if animal manure has entered the plant or not, is considered as an organic fertiliser, and has to be spread out at a maimum rate of 170 kg of N/ha. 9.6 Are there any subsidies for treating digestate? In none of the member states there are direct subsidies for treating digestate. However, in some of them, the subsidies for renewable energy are directly linked to digestate treatment. In Germany for eample, a requirement for the remuneration of renewable energy production from digesting organic waste is that it is necessary to apply a postrotting after the digestion process. In Flanders, cogeneration units at anaerobic digestion plants are subsidised, only if the produced heat is used in an efficient way. Drying digestate with this heat is recognised as an efficient way to use the produced heat. However, in Luembourg for eample the use of waste heat from biogas plants for drying of digestate is not eligible for waste heat use bonus for commercialised heat. References Amon, T., Amon, B., Kryvoruchko, V., et al. (2006) Optimising methane yield from anaerobic digestion of manure: Effects of dairy systems and of glycerine supplementation. International Congress Series, 1293, 217220. AEBIOM (2013). European Bioenergy Outlook 2013, statistical report. Barth, J. (2006): Quality and markets for compost and digestion residues in Europe. The 1st Baltic Biowaste Conference, Tallinn, Estonia, www.recestonia.ee/ecn/presentations/9%20josef%20barth.pdf (accessed 03 June 2012) Bak, T., Membrez, Y., Mottet, et al. (2009): État de l art des méthodes (rentables) pour l élimination, la concentration ou la transformation de l azote pour les installations de biogaz agricoles de taille petite/ moyenne. Federal Department for the Environment, Transports, Energy and Communication (DETEC), Switzerland, [in French]. Claeys, J. (2014). Personal communication Inagro. Cougnon, M., Vanden Nest, T., Reheul, D. (2012). Gebruik en werking digestaatproducten in de akkerbouw. Onderzoeksproject in opdracht van VLACO. Verslag 2012. UGent, Vakgroep Plantaardige Productie. CSES (2010). Evaluation of Regulation EC 2003/2003 relating to fertilizers Final Report. November 2010 De Haas, M.J.G. en van Dijk, T.A. (2010). Inventarisatie klimaatvriendelijke kunstmest. Rapport 1379.09, Nutriënten management instituut, Wageningen. De Mol, R.M. and Hilhorst, M.A. (2003) Methaan, lachgas en ammoniakemissies bij productie, opslag en transport van mest. IMAG Rapport 200303. Deck, J. and En Deboosere, S. (2005) Manure treatment according to the TREVIconcept. De Vries, J.,W., Groenestein, C.,M. and de Boer, I.,J.,M. (2012) Environmental consequences of processing manure to produce mineral fertilizer and bioenergy. Journal of Environmental Management, 102, 173183. European Biogas Association. Biogas report 2014. EC European Commission (2010) International Reference Life Cycle Data System (ILCD) Handbook General guide for Life Cycle Assessment. Publications Office of the European Union. Delfosse, P. (2014): Public Research Centre Gabriel Lippmann, Personal communication Fien P.E. and Johnston A.M. (2012). World fertilizer nutrient reserves: a view to the future. J. Sci. Food Agr., 92, 5, 10011005 Frischknecht, R., Jungbluth, N., Althaus, H.J., et al. (2007) Implementation of Life Cycle Impact Assessment Methods. Ecoinvent report No. 3, v2.0. Swiss Centre for Life Cycle Inventories, Dübendorf. Goedkoop, M., Heijungs, R., Huijbregts, M., et al. (2009) ReCiPe 2008. A life cycle impact assessment method which comprises harmonised category indicators at the midpoint and the endpoint level. Report I: Characterisation, Ministry of Housing, Spatial Planning and Environment (VROM). Retrieved from http://www.lciarecipe.info Golkowska, K., VázquezRowe, I., Lebuf, V., Accoe, F., Koster, D., (2014): Assessing the costs and value of output products in digestate treatment systems. In: Water Science & Technology, 69(3), 656662. Golkowska, K., VázquezRowe, I., Koster D., Lebuf, V., Benetto, E., Vaneekhaute, C., Meers, E. (2015). Life Cycle Assessment on selected processes of nutrient recovery from digestate, in The recovery and use of mineral nutrients from organic residues (eds. Meers, E., Velthof, G.), John Wiley & Sons, in preparation. 26 27

Gomand, A. (2013). Een goede bemesting is een puzzel. Powerpoint voor de vakgroep 28 februari 2013. Grauwels, K. (2014). Personal communication Mestbank. Hill Laboratories, 2002. Crop guide: lettuce. R J Hill Laboratories, Hamilton, New Zealand. Available from: http://www.hilllaboratories.com. IPCC International Panel on Climate Change (2013): Climate Change 2013. The Physical Science Basis. Working Group I. Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change. IWTHOBU (2002). Kenmerken, samenstelling, landbouwkundige waarde en toepassingsgebied van digestaat. Platform voor implementatie van anaërobe vergisting in Vlaanderen. Jaeken, P. (2012). Potential for organic and manure derived products as raw material for the mineral fertilizer industry. Powerpoint. Belfertil. Environmental assessment of digestate treatment technologies using LCA methodology. Waste Management, accepted. Velthof, G. (2012). Use of mineral concentrate from manure as fertilizer. Presentation 11/08/2012. Verlinden, G. (2005). Eindrapport: valorisatie van resteffluenten afkomstig van de mestverwerking. Deel 1: Literatuurstudie. Bodemkundige Dienst van België, WestVlaamse Proeftuin voor Industriële Groenten vzw, Interprovinciaal Proefcentrum voor de Aardappelteelt vzw. Villalba G., Liu Y., Schroder H., Ayres R.U. (2008). Global phosphorus flows in the industrial economy from a production perspective. J. Ind. Ecol., 12, 4,557569 WRAP (2011). New markets of digestate from anaerobic digestion. Aug 2011. Kellner, U., Delzeit, R., Thiering, J. (2011): Digestate treatment: The influence of the location and size of the plant on the cost. Berichte über Landwirtschaft, 89(1), 3855. Lebuf, V., Accoe, F., Van Elsacker, S., Vaneeckhaute, C., Michels, E., Meers, E., Ghekiere, G., Ryckaert, B. (2013). Techniques for nutrient recovery from digestate. Inventory report in the framework of the ARBOR Interreg IVB project. Available from: http://arbornwe.eu. Nemecek, T., Kägi, T. and Blaser, S. (2007) Life cycle inventories of agricultural production systems. Final report ecoinvent v2.0 No. 15. Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland. Nieuwe Oogst (2012). Mogelijk alternatief voor kunstmest. Editie 4 februari 2012. Rehl, T., (2012): Drying technologies for digestate treatment. Emissions of ammonia and nitrous oides during drying. Stuttgart. Personal communication. Rooyackers, B. (2009). Gebruikershandleiding spuiwater uit de chemische luchtwasser. Mestac. Sigurnjak, I. Michels, E. Crappé, S. Tack, F.M.G. Meers, E. Biobased mineral fertilizer substitutes for greenhouse crop production: a field scale assessment. To be published (2014). Smit A.L., Bindraban P.S., Schröder J.J., Conijn J.G., van der Meer H.G. (2009). Phosphorus in agriculture:global resources, trends and developments. Report 282. Plant Research International, Wageningen, the Netherlands. TCB, Technische Commissie Bodem (2010). Advies toedienen mineralenconcentraat. Brief aan de minister van Landbouw. Van Dijk, W. (2014). Personal communication ACRRES, the Netherlands. Vaneeckhaute, C. Meers, E. Michels, E. Ghekiere, G. Accoe, F. Tack, F.M.G. Closing the nutrient cycle by using biodigestion waste derivatives as synthetic fertilizer substitutes: A field eperiment. Biomass and bioenergy 55 (2013) 175189. Van Geel, W. (2012). Beproeving mineralenconcentraten en spuiwater in diverse gewassen. Resultaten uit onderzoek PPO en andere WURinstituten. PPOAGV, 8112012, Bergeijk Van Vuuren D.P., Bouwman A.F., Beusen A.H.W. (2010). Phosphorus demand for the 19702100 period: a scenario analysis of resource depletion. Global Environ. Chang., 20, 428 439 VázquezRowe, I., Golkowska, K., Lebuf, V., Vaneeckhaute, C., Michels, E., Meers, E., Benetto, E., Koster, D. (2015). 28 29

30 31

Notes 32 33

34 35

Improving sustainable biomass utilisation in North West Europe Project Partners www.arbornwe.eu